Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Komatsu, Seiji; Nishida, Tetsuro; Kawasaki, Ichio; Gunji, Hikaru; Nishino, Shohei; Kambara, Takashi*; Miura, Hirohito*; Suzuki, Takaichi*; Kinoshita, Masato*; Kanei, Tatsuya*
Nihon Hozen Gakkai Dai-21-Kai Gakujutsu Koenkai Yoshishu, 5 Pages, 2025/07
Steam used for process and air conditioning in each facility at the Nuclear Fuel Cycle Engineering Institute is generated by a water tube boiler installed in the Institute's central control room and supplied to each facility via underground trenches. There are three steam supply pipelines (A, B, and C) to each facility, with two of these (A and B) designated for the reprocessing facility. The steam pipelines, including expansion joints and steam traps, are covered with insulation. The two steam pipelines for the reprocessing facility (A and B) are laid parallel, creating a structure that makes inspection and maintenance difficult. In particular, the expansion joints are spaced very closely between the A and B lines, making insulation removal difficult, which has been a challenge in performing visual inspections of the expansion joint bodies. This paper reports on the features and effects of an improved insulation system designed to allow for easy removal and installation.
Kokubun, Yuji; Hosomi, Kenji; Seya, Natsumi; Nagaoka, Mika; Inoue, Kazumi; Koike, Yuko; Hasegawa, Ryo; Kubota, Tomohiro; Hirao, Moe; Iizawa, Shogo; et al.
JAEA-Review 2024-053, 116 Pages, 2025/03
JAEA-Review-2024-053.pdf:3.26MB
Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution prevention act, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2023. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Kokubun, Yuji; Nakada, Akira; Seya, Natsumi; Nagaoka, Mika; Koike, Yuko; Kubota, Tomohiro; Hirao, Moe; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; et al.
JAEA-Review 2023-052, 118 Pages, 2024/03
JAEA-Review-2023-052.pdf:3.67MB
Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2022. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Ishiyama, Toru; Kawasaki, Ichio; Miura, Hirohito*
Nihon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.33 - 36, 2014/07
There are 4-boiler systems in NCL. These boilers have been operated in the long term over 20 years. One of them, the leakage of boiler water was found at one of the generating tubes, and 2 adjoining generating tubes were corroded in Dec, 2011. These generating tubes were investigated by immersion ultrasonic testing (UT) for measure thickness of the tube. As a result, thinner tube was found in a part of a bend and near the water drum. These parts are covered with sulfide deposit, it seems that the generating tubes were corroded by sulfide.